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Vedolizumab drug levels

Blood Sciences Test

**Please note; delay vedolizumab drug and antibody level analysis **

Due to a manufacturing issue which is outside of our control, there will be a delay in vedolizumab drug and anti-drug antibody analysis. We are actively working hard to resolve the problem and will resume the service as soon as possible.  If you would like to discuss this, please contact the Duty Biochemist rde-tr.biochem@nhs.net 01392 402935 (option 2 then option 1). We apologies for any inconvenience this delay may cause.



Special instructions

Trough (pre dose) specimen required



Test Price


*NHS referral price

Test Usage

Managing inflammatory diseases with biological medicines such as Vedolizumab is challenging. Patients may respond well to treatment initially, only to encounter loss of response further ahead in their treatment pathway. Others may not respond to treatment at all. One approach to potentially improve outcomes for patients on Vedolizumab is to measure trough drug levels. However, drug level testing will only be useful if it actually creates positive outcomes for patients. The challenge lies in optimising when this analysis takes place and how best to interpret the data in making clinical decisions that benefit patients. It is widely accepted that undetectable drug level is associated with poor clinical outcomes.

Vedolizumab Therapeutic Drug Monitoring:

The clinical utility of vedolizumab TDM is currently uncertain.

Post hoc analyses of the Gemini registration trials (1) and real-world data (2-4) demonstrate that higher vedolizumab trough levels during induction correlate with higher clinical and endoscopic outcomes in IBD patients.  Whether lower drug levels exacerbate disease activity, or whether higher disease activity results in lower drug levels, remains uncertain.  Prospective studies are required to demonstrate the impact of vedolizumab dose optimisation based on drug levels.

High BMI and low serum albumin levels are predictive of low vedolizumab levels.

A propensity score-based case-matched analysis of UC patients in the Gemini I trials (5) using patient level data, adjusting for confounding factors affecting drug clearance and serum levels suggest target vedolizumab trough levels of:

  • 37.1 mg/L at week 6
  • 18.4 mg /L at week 14
  • 12.7 mg/L during maintenance treatment.

Although prospective studies are required to demonstrate clinical utility, based on experience of anti-TNF TDM possible uses of vedolizumab TDM include:

Proactive TDM

  • A week 6 drug level might help inform decision as to whether to give a week 10 dose

Reactive (in the setting of treatment failure):

  • vedolizumab drug level <3.0 mg/L AND positive antibodies – suggest stop vedolizumab
  • vedolizumab drug level <12.7 mg/L – suggest increase dose of vedolizumab as higher vedolizumab trough levels during induction correlate with higher clinical and endoscopic outcomes in IBD patients.


  1. Rosario M et al JCC 2017;11:921-9
  2. Williet N et al Clin Gastroenterol Hepatol 2017;15:1750-1757
  3. Dreesen E et al Clin Gastroenterol Hepatol 2018;16:1937-1946
  4. Ungaro R et al JCC 2019
  5. Ostermann MT et al APT 2019;49:408-18


Local test, can be added on to an existing request

Turnaround time

4 weeks


We welcome referrals for Vedolizumab monitoring. If you are a new requestor please complete the following form: New requestor form. 

We now also have the option to use NPEx for referral requesting.

Our Quality Statement for referred work can be found here :  Quality statement May 2019 (134 downloads)


Specimen Labelling Procedure
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